首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   126440篇
  免费   43864篇
  国内免费   265篇
耳鼻咽喉   1983篇
儿科学   5919篇
妇产科学   1850篇
基础医学   22864篇
口腔科学   5762篇
临床医学   16952篇
内科学   34094篇
皮肤病学   8482篇
神经病学   18690篇
特种医学   3217篇
外科学   17614篇
综合类   299篇
现状与发展   1篇
一般理论   64篇
预防医学   8909篇
眼科学   2052篇
药学   9397篇
中国医学   1135篇
肿瘤学   11285篇
  2024年   91篇
  2023年   693篇
  2022年   1458篇
  2021年   3605篇
  2020年   6283篇
  2019年   12235篇
  2018年   11767篇
  2017年   12727篇
  2016年   13519篇
  2015年   13545篇
  2014年   13972篇
  2013年   15080篇
  2012年   8400篇
  2011年   8324篇
  2010年   11079篇
  2009年   7108篇
  2008年   5266篇
  2007年   4136篇
  2006年   3850篇
  2005年   3356篇
  2004年   3167篇
  2003年   2899篇
  2002年   2766篇
  2001年   975篇
  2000年   841篇
  1999年   488篇
  1998年   352篇
  1997年   295篇
  1996年   204篇
  1995年   193篇
  1994年   192篇
  1993年   147篇
  1992年   112篇
  1991年   88篇
  1990年   71篇
  1989年   82篇
  1988年   74篇
  1987年   72篇
  1986年   62篇
  1985年   63篇
  1984年   86篇
  1983年   70篇
  1982年   79篇
  1981年   68篇
  1980年   64篇
  1979年   34篇
  1978年   40篇
  1977年   35篇
  1976年   31篇
  1974年   26篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Between March 2012 and August 2013, 591 quality forms were filled out for abdominal organs in the Netherlands. In 133 cases (23%), there was a discrepancy between the evaluation from the procuring and transplanting surgeons. Injuries were seen in 148 (25%) organs of which 12 (2%) led to discarding of the organ: one of 133 (0.8%) livers, five of 38 (13%) pancreata and six of 420 (1.4%) kidneys (P < 0.001). Higher donor BMI was a risk factor for procurement‐related injury in all organs (OR: 1.06, P = 0.011) and donor after cardiac death (DCD) donation in liver procurement (OR: 2.31, P = 0.034). DCD donation is also associated with more pancreata being discarded due to injury (OR: 10.333, P = 0.046). A higher procurement volume in a centre was associated with less injury in pancreata (OR = −0.95, P = 0.013) and kidneys (OR = −0.91, P = 0.012). The quality form system efficiently monitors the quality of organ procurement. Although there is a relatively high rate of organ injury, the discard rate is low and it does not significantly affect 1‐year graft survival for any organ. We identified higher BMI as a risk factor for injury in abdominal organs and DCD as a risk factor in livers. A higher procurement volume is associated with fewer injuries.  相似文献   
992.
Transplant options for patients with type 1 diabetes and end‐stage renal disease (ESRD) include deceased donor kidney, live donor kidney (LDK) and simultaneous pancreas‐kidney (SPK) transplantation. The aim of this study was to compare outcomes between LDK and SPK for patients with type 1 diabetes and ESRD in the UK. Data on all SPK (n = 1739) and LDK (n = 385) transplants performed between January 2001 and December 2014 were obtained from the UK Transplant Registry. Unadjusted patient and kidney graft survival were calculated using the Kaplan–Meier method. Multivariate analysis of kidney graft and patient survival was performed using Cox proportional hazards regression. There was no significant difference in patient (P = 0.435) or kidney graft survival (P = 0.204) on univariate analysis. On multivariate analysis there was no association between LDK/SPK and patient survival [HR 0.71 (0.47–1.06), P = 0.095]. However, LDK was associated with an overall lower risk for kidney graft failure [HR 0.60 (0.38–0.94), P = 0.025]. SPK recipients with a functioning pancreas graft had significantly better kidney graft and patient survival than LDK recipients or those with a failed pancreas graft. SPK transplantation does not confer an overall survival advantage compared to LDK. However, those SPK recipients with a functioning pancreas have significantly better outcomes.  相似文献   
993.
Direct‐acting antiviral agents (DAA) combining daclatasvir (DCV) have reported good outcomes in the recurrence of hepatitis C virus (HCV) infection after liver transplant (LT). However, its effect on the severe recurrence and the risk of death remains controversial. We evaluated the efficacy, predictors of survival, and safety of DAC‐based regimens in a large real‐world cohort. A total of 331 patients received DCV‐based therapy. Duration of therapy and ribavirin use were at the investigator's discretion. The primary end point was sustained virological response (SVR) at week 12. A multivariate analysis of predictive factors of mortality was performed. Intention‐to‐treat (ITT) and per‐protocol SVR were 93.05% and 96.9%. ITT‐SVR was lower in cirrhosis (n = 163) (96.4% vs. 89.6% P = 0.017); the SVR in genotype 3 (n = 91) was similar, even in advanced fibrosis (96.7% vs. 88%, P = 0.2). Ten patients (3%) experienced virological failure. Therapy was stopped in 18 patients (5.44%), and ten died during treatment. A total of 22 patients (6.6%) died. Albumin (HR = 0.376; 95% CI 0.155–0.910) and baseline MELD (HR = 1.137; 95% CI: 1.061–1.218) were predictors of death. DCV‐based DAA treatment is efficacious and safe in patients with HCV infection after LT. Baseline MELD score and serum albumin are predictors of survival irrespective of viral response.  相似文献   
994.
Hypertrophic scar is a major clinical outcome of deep‐partial thickness to full thickness thermal burn injury. Appropriate animal models are a limitation to burn research due to the lack of, or access to, animal models which address the endpoint of hypertrophic scar. Lower species, such as rodents, heal mainly by contracture, which limits the duration of study. Higher species, such as pigs, heal more similarly to humans, but are associated with high cost, long duration for scar development, challenges in quantifying scar hypertrophy, and poor manageability. Here, we present a quantifiable deep‐partial thickness burn model in the rabbit ear. Burns were created using a dry‐heated brass rod for 10 and 20 seconds at 90 °C. At the time of eschar excision on day 3, excisional wounds were made on the contralateral ear for comparison. Burn wound progression, in which the wound size expands over time is a major distinction between excisional and thermal injuries, was quantified at 1 hour and 3 days after the injuries using calibrated photographs and histology and the size of the wounds was found to be unchanged from the initial wound size at 1 hour, but 10% in the 20 seconds burn wounds at 3 days. A quantifiable hypertrophic scar, measured by histology as the scar elevation index, was present in both 20 seconds burn wounds and excisional wounds at day 35. ImageJ measurements revealed that the 20 seconds burn wound scars were 22% larger than the excisional wound scars and the 20 seconds burn scar area measurements from histology were 26% greater than in the excisional wound scar. The ability to measure both burn progression and scar hypertrophy over a 35‐day time frame suits this model to screening early intervention burn wound therapeutics or scar treatments in a burn‐specific scar model.  相似文献   
995.
Oxygen is an important factor for wound healing. Although several different therapies investigated the use of oxygen to aid wound healing, the results of these studies are not unequivocal. This systematic review summarizes the clinical and experimental studies regarding different oxygen therapies for promoting wound healing, and evaluates the outcomes according the methodological details. A systematic literature search was conducted using Embase, Medline, Web of Science, Cochrane, PubMed publisher, and Google Scholar libraries. Clinical and experimental studies investigating oxygen for wound healing were selected. Included articles were categorized according to the kind of therapy, study design, and wound type. The methodological details were extracted and analyzed. Sixty‐five articles were identified and divided in three different oxygen therapies: Local oxygen therapy, hyperbaric oxygen therapy, and supplemental inspired oxygen therapy. More than half of the included local oxygen and hyperbaric oxygen studies had one or more significant positive outcomes, 77 and 63%, respectively. Supplemental inspired oxygen therapy during gastrointestinal and vascular surgery was more likely to have a positive result than during other surgical interventions reducing surgical site infections. These many positive outcomes promote the use of oxygen treatment in the stimulation of wound healing. However, the lack of clinical studies and vast methodological diversity made it impossible to perform a proper comparison within and between the different therapies. Further randomized clinical studies are warranted to examine the value of these therapies, especially studies that investigate the more patient‐friendly oxygen dressings and topical wound oxygen therapies. Also, to achieve more solid and consistent data, studies should use more standardized methods and subjects.  相似文献   
996.
997.
998.
999.
1000.
Cutaneous squamous cell carcinoma (SCC) is a malignancy that arises from epidermal keratinocytes. Although the majority of cutaneous SCC cases are easily treated without further complication, some behave more aggressively and carry a poor prognosis. These “high‐risk” cutaneous SCCs commonly originate in the head and neck and have an increased tendency toward recurrence, local invasion, and distant metastasis. Factors for high‐risk cutaneous SCC include large size (>2 cm), a deeply invasive lesion (>2 mm), incomplete excision, high‐grade/desmoplastic lesions, perineural invasion (PNI), lymphovascular invasion, immunosuppression, and high‐risk anatomic locations. Both the National Comprehensive Cancer Network® (NCCN®) and the American Joint Committee on Cancer (AJCC) identify several of these high‐risk features of cutaneous SCC. The purpose of this article was to review the high‐risk features included in these guidelines, as well as their notable discrepancies and omissions. We also provide a brief overview of current prophylactic measures, surgical options, and adjuvant therapies for high‐risk cutaneous SCC. © 2016 Wiley Periodicals, Inc. Head Neck 39: 578–594, 2017  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号